A motor vehicle which has and uses at least one electric motor for driving or propelling said motor vehicle, is referred to as an electric vehicle or hybrid vehicle. In this context, the at least one electric motor is to be supplied with electrical energy during a driving mode of the motor vehicle from at least one electrical energy store, which can also be referred to as a battery or accumulator. This at least one electrical energy store can be, for example, a high-voltage battery. The latter is to be supplied in turn with electrical energy in a charging mode. The high-voltage battery can be charged from an external power grid via a charging socket. However, since the infrastructure for the accessible power grid is very different depending on the locality, according to the current state of the art a high-voltage booster for charging with direct current (DC charging) and an on-board charger (OBC) for charging with alternating current (AC charging) are provided in every vehicle. The two components transform the incoming current to the direct current which is required to charge the battery and which has, for example, a voltage of 800 V. It would be desirable to combine the functions of the high-voltage booster and of the on-board charger in a single vehicle charger instead of having two separate units.
DE 10 2011 118 957 A1, which is incorporated by reference herein, describes an electrically driven vehicle with two charging sockets. The charging sockets can be embodied as a pure AC socket or DC socket or as a combined AC/DC socket.
JP 2000/134720 A, which is incorporated by reference herein, discloses an electrically driven vehicle which can be charged with AC or DC current. Separate circuits for AC current and DC current are respectively provided.
DE 10 2013 225 493 A1, which is incorporated by reference herein, discloses an electrically driven vehicle which charges the high-voltage battery with alternating current via an on-board charger. A DC/DC voltage converter which is connected to the OBC is provided for charging a second low-voltage battery.
EP 2 542 439 B1, which is incorporated by reference herein, also describes a vehicle which can be charged with AC current or DC current and in which separate circuits for AC current and DC current are respectively provided. The voltage of the DC power source must correspond to the voltage which is required for charging the high-voltage battery.
EP 2 875 984 A2 (U.S. Pat. No. 9,238,415 B2), which is incorporated by reference herein, discloses an electrically driven vehicle which can be charged simultaneously with AC current and DC current. What is referred to as an inverter charging system is disclosed in which the main charging current is supplied by the DC power source, and the AC power source supplies a correction current which reduces the harmonics in the charging current and permits a high level of efficiency to be achieved. The voltage of the DC power source must correspond to the voltage which is required for charging the high-voltage battery.